Modulation of active oxygen during pathogenesis of Pseudomonas syringae.

丁香假单胞菌在植物组织中的成功定植似乎需要处理由相互作用早期产生的HOOH引起的氧化应激的能力。发现丁香假单胞菌的过氧化氢酶活性比其非致病性亲戚荧光假单胞菌和恶臭假单胞菌高10至100倍。在丁香假单胞菌裂解物中检测到至少8种过氧化氢酶同工酶。甘氨酸品种4。其中两种同工酶是外周质所特有的。丁香假单胞菌过氧化氢酶活性与培养的生长阶段有关。细胞质过氧化氢酶的比活性在过渡到固定期时增加。这些结果与多种过氧化氢酶同工酶参与这些细菌发病过程中氧化应激的减少是一致的。

Successful colonization of plant tissue by Pseudomonas syringae appears to require the ability to cope with oxidative stree caused by the HOOH produced during early phases of the interaction. P. syringae strains were found to contain 10 to 100-fold higher levels of catalase activity than their nonpathogenic relatives, P. fluorescens and P. putida. At least 8 catalase isozymes were detected in lysates of P. syringae pv. glycinea race 4. Two of these isozymes were unique to the periplasm. Catalase activity in P. syringae strains was dependent on the growth phase of the culture. The specific activity of cytoplasmic catalases increased during the transition to stationary phase. These results are consistent with the involvement of multiple catalase isozymes in the reduction of oxidative stress during pathogenesis by these bacteria.